chore: add VRE stack configs (JupyterHub + Zeppelin) + lakehouse components

- Add VRE directory with JupyterHub + Zeppelin docker-compose configs
- Add Gravitino, Flink, Kafka, MinIO, Trino lakehouse stack
- Add Superset, Metabase, StarRocks analytics tools
- Session reprise après crash 2026-06-01

Infrastructure: 86 conteneurs total
Known issues: Kafka (no ZK conn), Trino (node.env null), JupyterHub (DB path)

vre/jupyterhub/start.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+set -e
+
+# Ensure the data directory exists
+mkdir -p /srv/jupyterhub
+
+# If the DB doesn't exist, initialize it  
+if [ ! -f /data/jupyterhub.sqlite ]; then
+    echo "Initializing JupyterHub database..."
+fi
+
+# Run JupyterHub with DB in /data volume
+export JUPYTERHUB_DATA=/srv/jupyterhub
+
+exec jupyterhub -f /srv/jupyterhub/jupyterhub_config.py